If something really gets to you at school, take a long deep breath and remind yourself that, after all, school is temporary. Soon you will be on to the next class, on to the next grade, and this won't matter at all. When adults are in their 20s, they barely remember what happened in elementary school. As you take on your real job, your real life, the school stuff fades very much into distant memory. You will barely remember what went on. I know it seems excruciatingly important right now, but in the grand scheme of things it is just a drop in the ocean. Look on it as a learning experience, and let it slide.